WEBVTT 00:00:00.750 --> 00:00:02.049 Air quality explained. 00:00:03.799 --> 00:00:06.780 Air quality is a measure of how clean or polluted the air is. 00:00:07.869 --> 00:00:09.310 The two main culprits of poor air 00:00:09.319 --> 00:00:12.250 quality are particulate matter and ground-level ozone. 00:00:13.779 --> 00:00:17.510 Particulate matter or airborne particles includes dust, dirt, soot, 00:00:17.620 --> 00:00:18.399 and smoke. 00:00:19.219 --> 00:00:20.840 These particles are so small that they 00:00:20.850 --> 00:00:23.430 can be inhaled causing serious health problems. 00:00:27.010 --> 00:00:29.829 The smallest are a fraction of the size of a human hair, 00:00:29.840 --> 00:00:31.530 even smaller than grains of sand. 00:00:34.380 --> 00:00:38.290 Ground-level ozone, on the other hand, is a gas and the main ingredient in smog. 00:00:39.200 --> 00:00:41.139 It forms when certain pollutants chemically react 00:00:41.150 --> 00:00:43.020 in the presence of heat and sunlight. 00:00:43.979 --> 00:00:46.959 Even low concentrations can trigger a variety of health problems. 00:00:48.689 --> 00:00:50.299 It can cause respiratory issues, 00:00:50.310 --> 00:00:53.500 hospitalization for heart or lung diseases, and even death. 00:00:53.860 --> 00:00:59.060 The EPA estimates that poor air quality causes more than 100,000 deaths in the US annually. 00:00:58.340 --> 00:00:59.060 00:00:59.560 --> 00:01:00.619 Seniors, children, 00:01:00.840 --> 00:01:03.740 and those with compromised immune systems are especially at risk. 00:01:04.910 --> 00:01:06.410 How can you protect yourself? 00:01:08.169 --> 00:01:11.809 Outdoor activity and exercise of all kinds can help your heart stay healthy 00:01:11.919 --> 00:01:12.790 and resilient, 00:01:13.550 --> 00:01:15.680 but stay inside when the air quality is poor. 00:01:16.949 --> 00:01:19.449 If you must go out, limit your time outside. 00:01:22.550 --> 00:01:26.000 The air quality index, or AQI, reports the daily air quality. 00:01:26.110 --> 00:01:28.260 It tells you how clean or polluted your air is 00:01:28.269 --> 00:01:30.879 and what associated health effects might be a concern for you. 00:01:30.599 --> 00:01:30.879 00:01:31.290 --> 00:01:34.730 See the current AQI for your area at airnow.gov.